OpenLayers.mobile.js - a mobile focused build --> Includes a subset of
the OpenLayers library to serve common mobile web app use cases. This
build provides access to OpenStreetMap, Bing, WMS, WFS and vector
layers; touch optimized controls; geolocation; vector editing and
interaction tools. The examples tagged mobile can use this build.
so it doesnt have lots of feature of openlayers. if you want to learn what it has you can check out from
openlayers / build / mobile.cfg here.
you can find mobile version under OpenLayers github account. but you have to deploy mobile version for openlayers. Deploying (Shipping OpenLayers in your Application) can help you...
The OpenLayers build tool supports several different forms of
profiles to create customized OpenLayers builds with only the
components you need.
When building a file, you can choose to build with several different
compression options to the Python-based build.py script.
i hope it helps you...